Load Testing Page Load Time Performance Testing UI Testing

2 minutes read

During Speed testing of your website or web application using LoadFocus (https://loadfocus.com/website-speed-testing) on the Advice section you might get the tip that you need to enable compression like in the image below:

advice_enable_compression

Compressing responses often significantly reduces the size of transmitted data.
Because the compression happens at runtime this can add a big processing overhead which can affect the performance in a negative way.

Nginx if configured correctly compresses the responses before sending them to the clients and does not double compress the responses which have been already compressed.

In the next tutorial we will show how you can enable compression in case you are using Nginx to serve your files.

1. First locate the Nginx configuration file – nginx.conf
2. Once you located the file open the file and make sure that inside the configuration you can find the following flags:


gzip on;
gzip_disable "msie6";


gzip_vary on;
gzip_proxied any;
gzip_comp_level 5;
gzip_buffers 16 8k;
gzip_http_version 1.1;
gzip_min_length 1000;
gzip_types text/plain text/css application/json application/x-javascript text/xml application/xml application/xml+rss text/javascript;

3. Explanation of the flags:

LoadFocus.com is a Cloud Testing Platform used for Load and Performance Testing for Websites and APIs and Website Speed Testing with Analytics.

Apache JMeter Test Automation

2 minutes read

In order to add an XPath Extractor to your JMeter script you need to begin by installing JMeter and create an HTTP Request. If you want to check how you can create a load test with Apache JMeter, please check our previous blog post.

Start by adding a XPath Extractor to your HTTP Request by following the below steps:

Select the HTTP Request on the left side, and Right-click it
Hover to Add -> Post Processors -> XPath Extractor
Click on XPath Extractor

adding-xpath-extractor

Update the XPath Extractor with the desired variable names and expected XPath. We are going to make an HTTP Request to http://example.com/ and based on the HTML response, we are going to extract the H1 tag from the website and use it in the next request.

Update the XPATH Extractor with the following details:

Reference Name: The name of the JMeter variable in which to store the result, var1
XPath Query: Element query in XPath language. Can return more than one match, //html//h1
Default Value: Default value returned when no match found. It is also returned if the node has no value and the fragment option is not selected, NOTFOUND

configure-xpath-extractor-jmeter

Copy the existing HTTP Request and add the variable in the Server Name:

www.example.com/${var1}

update-new-http-request-jmeter

In the View Results Tree, you can see that the variable var1 contains the content extracted from the XPATH //html//h1, Example Domain, and the second request is going to be:

GET http://www.example.com/Example Domain/

jmeter-xpath-extracted-variable

result-from-xpath-extractor

Have in mind that you can check the XPath also from inside the browser’s console, by typing the following:

 $x('//html//h1')

which should output the element’s content that was saved inside the ${var1} variable from XPath Extractor.

chrome-browser-console-xpath

In order to run load tests with thousands of threads (users) and to run load tests from different world locations, you can use LoadFocus.com which offers a cloud load testing service, easy to use, which keeps all your tests and test runs in the history automatically.

Load Testing Website Speed Testing

1 minute read

Get every month 5 free load tests and 5 free website speed tests to your Free plan by adding our code in your website.

Our Link Program lets you run 5 website load tests and 5 free website speed tests per month completely free!

Just add the LoadFocus link to your website to upgrade. Here is the link:


<a href="https://loadfocus.com/?utm_source=link" title="load testing tool"></a>

Once the link is visible on your site, we’ll automatically give you 5 load tests and 5 website speed tests per month for free.

LoadFocus.com is a Cloud Testing Platform used for Load and Performance Testing for Websites and APIs and Website Speed Testing with Analytics.

Load Testing Performance Testing Test Automation Uncategorized

5 minutes read

What are assertions ?

In case you are not familiar with the term, an assertion “is a test / a condition that must be tested to confirm conformance to a requirement”. Basically a test assertion is – a condition that compares the expected value with the actual value for a specified use case.

Why should I use assertions ?

Before we deliver a product, we need to run many test assertions to make sure the product meets the customer’s expectations. Also, you can check our intro blog post regarding how to run a load test with Apache JMeter.

Should we use assertions in the JMeter tests ?

Usually assertions are not used when we create the scripts for load or stress testing an application. Most of the tester that run
these kind of tests base their results only on the response status codes that the application under test returns. This might be a problem and might make the final results not accurate.

What are the cases in which not using an assertions may affect your final results ?

Not all the time a successfull response from the server (200 OK) means that the application responded as expected.
You may ask yourself and the a few cases are mentioned below:

the application redirects to a maintaince page
the application responds a 200 OK but sends an error message in the body of the response indicating a error message
the application redirects to an error page and sends back a 200 OK with and error message indicating why the error returns

To avoid these kind of errors to affect your performance report is a very good idea to use assertions:

in GET/POST/PUT/PATCH methods
in API performance testing
in functional testing

Be aware that if your are creating a long running test or a test with a lot of requests is good not to use a lot of assertions as
they tend to consume quite a bit of memory which could make your JMeter tool crash and means starting the test again.

What type of assertions does JMeter support ?

There are several types of assertions that you can use in your test scripts.
The most used ones are:

“Response Assertion“: the response assertion control panel lets you add pattern strings to be compared against various fields of the response
“XPath Assertion“: the XPath Assertion tests a document for well formedness, has the option of validating against a DTD, or putting the document through JTidy and testing for an XPath (if that XPath exists, the Assertion is true)
“HMTL Assertion“: the HTML Assertion allows the user to check the HTML syntax of the response data using JTidy.
“XML Assertion“: tests that the response data consists of a formally correct XML document; it does not validate the XML based on a DTD or schema or do any further validation.
“Compare Assertion“: can be used to compare sample results within its scope; either the contents or the elapsed time can be compared, and the contents can be filtered before comparison.
Compare Assertion MUST NOT BE USED during load test as it consumes a lot of resources (memory and CPU). Use it only for either functional testing or during Test Plan debugging and Validation.
“Size Assertion“: verifies that each response contains the right number of bytes in it; you can specify that the size be equal to,
greater than, less than, or not equal to a given number of bytes

How much do assertions consume in terms of CPU and memory ?

If the test that your are using is a long running test or makes a very large number of requests you may encounter unexpected failures related to “out of memory” errors or similar.

In terms of resources the HMTL Assertion, XML Assertion or Compare Assertion consume a lot of resources so is a good idea to avoid using those in long running tests. The other assertions does not have a very bad impact on the resources so they can be used without a problem.

Which is the scope to which the assertions apply ?

There are 3 cases related to which scope an assertion applies to:

1. applies to all the child requests

2. applies to all the sibling requests

3. applies only to one specific request

How to use a “Response Assertion” in JMeter ?

Response Assertion is one of the most widely used assertion as it allows to verify the content of the response, status code or headers.

It can be configured to verify:

the different segments of the response like text (response body)
the document type like pdf, doc etc
the headers
the response code (2xx, 4xx)
response message (description of code) and response headers
tests the response against a pattern string which can be a plain text or a Perl5 regular expression; the specified pattern is matched against the selected segment of the response

Let’s start by adding a response assertion that expects that the response code is 200.

We will now add another assertion that expects that the text “wikipedia” is present in the response of the server.

Running the script will show that that the request succeeded without any problem.

Now we will change the text of the second assertion to “dummy_text_inexistent” and run the test again.

In the next tutorials we will show you how to use the rest of the assertions that are supported in JMeter.

You can also use LoadFocus to load test your websites, APIs or any web-app with thousands of users from AWS cloud locations.

Page Load Time Website Speed Testing

2 minutes read

During Speed testing of your website or web application using LoadFocus (https://loadfocus.com/speedtests) on the Advice section you might get the tip that you need to enable compression like in the image below:

advice_enable_compression
The question is why and how do you do that ?

The response to the why is that enabling gzip compression can reduce the size of the transferred response by up to 80-90%;
This has the following benefits:
significantly reduces the amount of time it takes to download the resources
reduces data usage for the client
improves the time to first render of your pages
a better user experience for your customers
a better monetization for your web application

You can enable gzip compression for CSS and JavaScript files.
Apart from these any text data or XML files will also benefit from gzip compression. Don’t use gzip for image or other binary files.

Image file formats supported by the web, as well as videos, PDFs and other binary formats, are already compressed; using gzip compression on them won’t provide any additional benefit.

By default all modern browsers automatically negotiate gzip compression for all HTTP requests that are done.
To help you enable gzip compression on your server you can check out the following project

https://github.com/h5bp/server-configs

that contains the sample configuration files for quite a few different servers.
After you’ve finishes to enable compression on your server run the LoadFocus speed test again. This time the tip regarding to Enable compression should say that everything is fine.

LoadFocus.com is a Cloud Testing Platform used for Load and Performance Testing for Websites and APIs and Website Speed Testing with Analytics.

Apache JMeter Performance Testing

1 minute read

In case you want to easily start Apache JMeter load testing tool on your MAC OS, here some things which you help you get started.

Once you downloaded Apache JMeter, just go to the PATH where you’ve dowloaded it. For example, I’ve downloaded JMeter in my Downloads folder. Here are full details on how to run your first load test with JMeter.

Steps to Add JMeter to the PATH environment variable:

Open Command-Line (Terminal)
Type jmeter and press Enter
If JMeter is not in the PATH variable, you’ll get the following:
```
-bash: jmeter: command not found
```

This is what you should see in your terminal:


computer:bin user$ jmeter
-bash: jmeter: command not found
computer:bin user$ pwd
/Users/user/Downloads/apache-jmeter-2.13/bin
computer:bin user$ export PATH=$PATH:/Users/user/Downloads/apache-jmeter-2.13/bin
computer:bin user$ jmeter
org.apache.jmeter.testelement.TestPlan
org.apache.jmeter.control.gui.TestPlanGui

LoadFocus.com is a Cloud Testing Platform used for Load and Performance Testing for Websites and APIs and Website Speed Testing with Analytics.

Apache JMeter Load Testing Performance Testing Stress Testing

6 minutes read

Overview

We are going to present how to use Apache JMeter (open source load testing tool) in order to perform basic load and stress testing on your web application. We are going through each step and show how to use JMeter’s GUI (graphical user interface) in order to build a test plan, configure load tests, run test and inspect the results.

Apache JMeter is an open source Java application, so it can run on any OS (operating system) which supports JAVA 6 or later. JMeter is a load testing (performance testing) tool designed to run tests on any given URI endpoint, with configurable number of concurrent clients (users) and other useful test configurable metrics and inspect results. Test results can be viewed in charts, tables or can be exported in CSV or XML formats.

Prerequisites

In order to start using JMeter you need a machine that you can install and run JMeter on. By default JMeter runs as a GUI application, which requires more resources than a command line based application. In order to perform the load tests faster and without bottlenecks you can run JMeter in the non-graphical mode (details on how to start JMeter in non-graphical mode in the next post)
Please note that results can differ based on the web server where the web application is hosted. Factors that we need to take into account are:

system resources CPU, RAM Memory of the web server
system resources CPU, RAM Memory of the machine where JMeter is installed (from where the tests are executed)
location of the web server between the load test injector and the web server where the application is hosted (which affects the latency of the tests – use a cloud load testing tool in order to easily run load tests from different locations)

Install JMeter

Apache JMeter is very easy to install. Depending on the OS, there are different ways on how to do this.

In order to run JMeter, here is what you need to install:

Oracle JAVA or OpenJDK (6 or later)
Apache JMeter (2.11 or 2.13)

Make sure that after installing JAVA you add it to the $PATH environment variable. Here you can find how to add the JAVA to the $PATH environment variable for every OS .

To start JMeter on Windows OS you need to go to the folder where you unarchived JMeter binaries and just run $JMETER_HOME/bin/jmeter.bat batch file. Please see here how you can run JMeter on Mac.

So, once all is installed and JMeter is running you can start creating your first load test. For this demo we are going to use Apache JMeter 2.11 on Mac.

Build Test Plan

In order to create a load test, add a Thread Group, in order to configure the thread properties (load test configuration):

apache jmeter test plan

Start by adding a Thread Group to your Test Plan by following the below steps:

Select the Test Plan on the left side, and Right-click it
Hover to Add -> Threads (Users) -> Thread Group
Click on Thread Group

apache jmeter thread group

Configure the following properties which will be used to run your load test:

See more details

Number of threads (users): The number of concurrent clients/users JMeter is going to simulate. Set it to 10.
Ramp-up Period: How long JMeter should take to get all the threads started. Set it to 10.
Loop Count: Number of times to perform the test case. Set it also to 10.

apache jmeter thread group configuration

Now we add a HTTP Request Sampler which represents an individual request made by each thread.
To do this Add a HTTP Request Sampler to your Thread Group by following the below steps:

Select on the Thread Group on the left side, then Right-click it
Hover (mouse over) to Add -> Sampler -> HTTP Request
Click on HTTP Request

apache jmeter http sampler

In the HTTP Request Sampler, under Web server, set the URL in the Server Name or IP field (website URL i.e www.example.com or public IP address).

If you want to execute more than one HTTP Request by each thread (user), simply duplicate the HTTP Request Sampler and update the Server Name or IP. Here are the steps to duplicate the HTTP Request Sampler.

Select HTTP Request Sampler, then Copy it (Cmd/Control + C)
Select Thread Group, then Paste it (Cmd/Control + V)

Note: In our JMeter test we will continue to use only one HTTP Request Sampler.

Add HTTP Cookie Manager (optional)

If your web application uses Cookies, JMeter allows to add cookies which will be sent with each HTTP request. You can do that simply by adding the HTTP Cookie Manager by following these steps:

Select Thread Group, then Right-click it
Hover (mouse-over) Add -> Config Element -> HTTP Cookie Manager

Add HTTP Header Manager (optional)

In case you need to send specific headers with every request, JMeter allows to add headers by adding the HTTP Header Manager by following these steps:

Select Thread Group, then Right-click it
Hover (mouse-over) Add -> Config Element -> HTTP Header Manager

Add View Results in Table

You need to use JMeter’s Listeners in order to view the output of a load or stress test. One of the most used Listeners is the View Results in Table, which we’ll use in the post and here is how to add it to your Test Plan:

Select Thread Group, then Right-click it
Hover (mouse-over) Add -> Listener -> View Results in Table

apache jmeter results listener

Run your Test Plan

After installing everything needed in order to start Apache JMeter and after configuring the Test Plan, you can start running your test.

First, save the test plan with the .jmx extension.
Run the test by pressing the green arrow button in the toolbar or by pressing Cmd/Control + R keys.

apache jmeter results in tree

You’ll starting seeing results in the View Results in Table, important columns are Sample Time (ms), Status, Bytes and Latency. To understand better the errors and responses you can check out this post.

Sample Time (ms): Represents the number of milliseconds that the server took to serve the request (response + latency)
Latency (ms): Represents the number of milliseconds that elapsed between when JMeter sent the request and when an initial response was received

At the bottom of the View Results in Table, you can see the Average Sample Time in ms and the Standard Deviation.
According to the results, after running 100 samples the Average Sample Time in milliseconds was 133 ms. Latency is going to be affected by the geographic distance between the place from where the request is made to the place where the web server is hosted.

apache jmeter 100 samples

So, no error occurred on our test when running the 10 requests X 10 threads (users) = 100 samples, and the Sample Time was low 133 ms.

Increase the Load by changing the Threads (users) values

In order to make our load test more realistic, let’s change the Threads (Users) field to 300.
Clear the previous JMeter results by pressing Cmd/Control + E or by clicking the Clear icon in JMeter’s toolbar.

Start the test, and check the results again. As you can see, the Sample Time increased almost by 50% to 178 ms, however no errors occurred while running our load test with JMeter.

apache jmeter 3000 samples

Also, while running the tests, server side monitoring will be helpful, looking at metrics like CPU or Memory. In Windows you can monitor these stats by opening the PerfMon tool or in Linux by typing the top command in terminal.

You can extend the load test up to 1000 threads (users), to check how your system behaves and discover potential bottlenecks, memory leaks, performance issues. LoadFocus.com is a cloud load testing service and you can run load tests with thousands of threads (users).

Conclusion

JMeter is a useful load testing tool, which helps you find load testing issues, discover bottlenecks and increate performance of your web application. Feel free to experiment different values for the load test in order to understand how your web server behaves under heavy load. In order to add more plugins to your default JMeter installation, you can check the JMeter plugins add-ons or check here how to add JMeter plugins to JMeter.

Blog about Testing Tools and Testing Ideas

Enable gzip compression on NGINX

How to Use Apache JMeter’s XPath Extractor?

Free load tests and website speed tests every month

How to use assertions in Apache JMeter tests

What are assertions ?

Why should I use assertions ?

Should we use assertions in the JMeter tests ?

What are the cases in which not using an assertions may affect your final results ?

What type of assertions does JMeter support ?

How much do assertions consume in terms of CPU and memory ?

Which is the scope to which the assertions apply ?

How to use a “Response Assertion” in JMeter ?

Why enable compression on your server ?

How to Add JMeter to the PATH Environment Variable On Mac OS X

How To Use Apache JMeter To Load Test a Web Server

Overview

Prerequisites

Install JMeter

Build Test Plan

See more details

Add HTTP Cookie Manager (optional)

Add HTTP Header Manager (optional)

Add View Results in Table

Run your Test Plan

Increase the Load by changing the Threads (users) values

Conclusion

Recent Posts

Blog about Testing Tools and Testing Ideas

What are assertions ?

Why should I use assertions ?

Should we use assertions in the JMeter tests ?

What are the cases in which not using an assertions may affect your final results ?

What type of assertions does JMeter support ?

How much do assertions consume in terms of CPU and memory ?

Which is the scope to which the assertions apply ?

How to use a “Response Assertion” in JMeter ?

Overview

Prerequisites

Install JMeter

Build Test Plan

See more details

Add HTTP Cookie Manager (optional)

Add HTTP Header Manager (optional)

Add View Results in Table

Run your Test Plan

Increase the Load by changing the Threads (users) values

Conclusion

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